Revert of Do not produce dSYM file for the iOS Frameworks with bitcode (patchset #2 id:20001 of https://codereview.webrtc.org/2705163007/ )

Reason for revert:
Looks like this caused the iOS API Framework Builder to fail.

https://build.chromium.org/p/client.webrtc/builders/iOS%20API%20Framework%20Builder/builds/3487/steps/zip%20archive/logs/stdio

Zipping /b/rr/tmpkIyP1e/w/webrtc_ios_api_framework.zip...
Traceback (most recent call last):
  File "/b/rr/tmpkIyP1e/rw/checkout/scripts/slave/recipe_modules/zip/resources/zip.py", line 144, in <module>
    sys.exit(main())
  File "/b/rr/tmpkIyP1e/rw/checkout/scripts/slave/recipe_modules/zip/resources/zip.py", line 130, in main
    exit_code = zip_with_subprocess(root, output, entries)
  File "/b/rr/tmpkIyP1e/rw/checkout/scripts/slave/recipe_modules/zip/resources/zip.py", line 43, in zip_with_subprocess
    assert os.path.isdir(path), path
AssertionError: /b/c/b/iOS_API_Framework_Builder/src/out_ios_libs/WebRTC.dSYM/
step returned non-zero exit code: 1
@@@STEP_FAILURE@@@

Original issue's description:
> Do not produce dSYM file for the iOS Frameworks with bitcode
>
> Though dSYM files can be generated when building applications or libraries
> with bitcode. They cannot be used to symbolicate crash reports from
> applications. Instead, developers need to grab the real dSYM files, which
> are generated for each specific device type after uploading an iOS / tvOS
> application to App Store (or to a device using Xcode). Apple clearly warns
> about it in its documentation:
>
> https://developer.apple.com/library/content/technotes/tn2151/_index.html#//apple_ref/doc/uid/DTS40008184-CH1-SYMBOLICATION-BITCODE
>
> With that in mind, I believe that it would be better to not confuse
> developers by giving them dSYM files that are not very helpful with
> the bitcode-enabled framework. Thus, proposing the following modification
> to the building script, to generate dSYM by default only without
> the bitcode option. However, if some developers still want to get
> the dSYM files as a build-process artifact, when enabling bitcode,
> they can explicitly add --extra-gn-args enable_dsyms=true to the script.
>
> Let me know if it lgty.
>
> NOTRY=True
> BUG=None
>
> Review-Url: https://codereview.webrtc.org/2705163007
> Cr-Commit-Position: refs/heads/master@{#16836}
> Committed: https://chromium.googlesource.com/external/webrtc/+/d74517c52a6cd4172b1f3fdc4e624b6145ff5a0f

TBR=kjellander@webrtc.org,kthelgason@webrtc.org,VladimirTechMan@gmail.com
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=None
NOTRY=True

Review-Url: https://codereview.webrtc.org/2719773002
Cr-Commit-Position: refs/heads/master@{#16844}
diff --git a/tools-webrtc/ios/build_ios_libs.py b/tools-webrtc/ios/build_ios_libs.py
index 7af4771..25745e0 100755
--- a/tools-webrtc/ios/build_ios_libs.py
+++ b/tools-webrtc/ios/build_ios_libs.py
@@ -110,8 +110,7 @@
     gn_target_name = 'rtc_sdk_objc'
   elif build_type == 'framework':
     gn_target_name = 'rtc_sdk_framework_objc'
-    if not use_bitcode:
-      gn_args.append('enable_dsyms=true')
+    gn_args.append('enable_dsyms=true')
     gn_args.append('enable_stripping=true')
   else:
     raise ValueError('Build type "%s" is not supported.' % build_type)
@@ -178,32 +177,30 @@
     distutils.dir_util.copy_tree(
         os.path.join(lib_paths[0], SDK_FRAMEWORK_NAME),
         os.path.join(args.output_dir, SDK_FRAMEWORK_NAME))
+    try:
+      os.remove(os.path.join(args.output_dir, dylib_path))
+    except OSError:
+      pass
     logging.info('Merging framework slices.')
     dylib_paths = [os.path.join(path, dylib_path) for path in lib_paths]
     out_dylib_path = os.path.join(args.output_dir, dylib_path)
-    try:
-      os.remove(out_dylib_path)
-    except OSError:
-      pass
     cmd = ['lipo'] + dylib_paths + ['-create', '-output', out_dylib_path]
     _RunCommand(cmd)
 
     # Merge the dSYM slices.
-    lib_dsym_dir_path = os.path.join(lib_paths[0], 'WebRTC.dSYM')
-    if os.path.isdir(lib_dsym_dir_path):
-      distutils.dir_util.copy_tree(lib_dsym_dir_path,
-                                   os.path.join(args.output_dir, 'WebRTC.dSYM'))
-      logging.info('Merging dSYM slices.')
-      dsym_path = os.path.join('WebRTC.dSYM', 'Contents', 'Resources', 'DWARF',
-                               'WebRTC')
-      lib_dsym_paths = [os.path.join(path, dsym_path) for path in lib_paths]
-      out_dsym_path = os.path.join(args.output_dir, dsym_path)
-      try:
-        os.remove(out_dsym_path)
-      except OSError:
-        pass
-      cmd = ['lipo'] + lib_dsym_paths + ['-create', '-output', out_dsym_path]
-      _RunCommand(cmd)
+    dsym_path = os.path.join('WebRTC.dSYM', 'Contents', 'Resources', 'DWARF',
+                             'WebRTC')
+    distutils.dir_util.copy_tree(os.path.join(lib_paths[0], 'WebRTC.dSYM'),
+                                 os.path.join(args.output_dir, 'WebRTC.dSYM'))
+    try:
+      os.remove(os.path.join(args.output_dir, dsym_path))
+    except OSError:
+      pass
+    logging.info('Merging dSYM slices.')
+    dsym_paths = [os.path.join(path, dsym_path) for path in lib_paths]
+    out_dsym_path = os.path.join(args.output_dir, dsym_path)
+    cmd = ['lipo'] + dsym_paths + ['-create', '-output', out_dsym_path]
+    _RunCommand(cmd)
 
     # Modify the version number.
     # Format should be <Branch cut MXX>.<Hotfix #>.<Rev #>.